The present invention relates to a machine for wrapping sticks of food products.
In particular, reference is made throughout the following specification to products such as chewing gum, albeit with no limitation in scope implied.
Sticks of chewing gum typically present a flat rectangular appearance and are obtained from rectangular sheets corresponding in size to a multiple of the dimensions of the single sticks, each sheet consisting in a plurality of sticks arranged side by side, adjoining along a direction parallel to their respective longitudinal axes and connected one to the next by way of score lines.
The single sticks, fed in succession along a direction transverse to their longitudinal axes, are spaced apart one from the next by a given distance at the moment of being directed into the peripheral seats of an infeed wheel forming part of a wrapping unit.
The aforementioned distance, or pitch, is such as will allow each stick to be paired with a leaf of wrapping material at a successive wrapping wheel, and thereupon enveloped in the selfsame leaf of material while avoiding any interference with the stick preceding or following on the wheel.
In prior art machines, the sticks are flicked into the seats of the wheel by an ejector that engages the advancing sticks directly, striking each one in turn along one longitudinal edge in such a way that it enters the relative seat describing a trajectory substantially within the plane occupied by the selfsame sticks when engaged by the ejector.
Self-evidently, any variation in feed speed occasioned by a change of pitch, combined with the transfer method described above, will be liable to result in damage to the sticks, and in particular to the edges, given the impact generated by the mechanical elements of the ejector and by the surfaces of the aforementioned seats.
A further drawback accompanying the method described above derives from the inevitable tendency of the sticks to bounce uncontrollably off the bottom of the seat, becoming incorrectly positioned within the seat as a result.
It is clear that drawbacks of this nature, caused by any sudden acceleration, will impose insurmountable limits on the production tempo achievable by wrapping machines of the type operating by the method described above.
Accordingly, the object of the present invention is to provide a wrapping machine for sticks of chewing gum, such as will be unaffected by the drawbacks mentioned in connection with the prior art.